have you tried the Happiest Baby on the Block 5 S's and the Baby Whisperer's EASY method and the dream feed?
Dream Feed is where you put them to bed at say 8, then at 10 when you are ready to go to sleep you feed them while they are still asleep. This helps them last longer.
If they wake up and it hasn't been 4 hours, try everything you can to get them to go to sleep that is NOT feeding them. If you already aren't feeding her when she wakes, then try not picking her up when she wakes but rather just patting her. The goal is to get HER to go back to sleep on her own, not with your help. Last resort is feeding or holding.
You may want to try music on repeat in her room, room darkening blinds (I like using a piece of black felt and the scratchy side of velcro), and a fan on in her room. This will create an environment of sleep.
Here is EASY and the 5 S's if you don't know them...
try using the Baby Whisperer's EASY method for a schedule, and the Happiest Baby on the Block 5 s's method. Those two combined will make cio not be a needed thing (at that age)
EASY - when the baby wakes up it Eats. After you feed it, then it has Activity - bouncy seat, tummy time, sitting up and playing with toys, swing, exersaucer, etc. When the baby gets fussy check the B's - boredom, butt or burp. If it's none of those then off to Sleep. Don't wait for the baby to do more than get the tiniest bit fussy, then see what is causing the fusses - if it's just that they needed their diaper change do that, but if it's not the activity is boring, the butt is dirty or they have to burp, then put them down. This may happen after as short as 45 minutes, don't freak, it really means they are tired.
Now, to get them to sleep use the 5 s's. Swaddle the baby, hold the baby on their side and sway as they suck on something (paci, your knuckle or their finger/thumb) and make a shush noise. This will calm your baby. When the baby is calm, but not asleep yet, keeping them swaddled lay them in the bed. I like to pat them instead of sway after a minute or two cause you can still pat after they are put down but you can't sway, so pat the baby and continue patting gradually decreasing it as you put them in the bed. Also continue the shushing as you put them down, again gradually getting quieter.
If you do these two you will find a well rested, easily managed baby in no time.